Device for truing grinding wheels



0. SENDERP DEVICE FOR TRUlNG GRINDING WHEELS.

APPLICATION man JUNE 19'. 1920.

1 ,40795 Patented Feb. 28, 1922.

1i i T (1555 3 23 i il? 1% t PATENT OFFICE.

UNITED STATES" OTTO SENDER, OF SCI'IAFFHAUSEN, SWITZERLAND. V

DEVICE FOR 'IR'UING GRINDING Application filed June 10, .1920. Serial No; 387,984.

To all whom it may concern 4 Be itknown that I, O'rroSENnER, a citizen of the Republic of Switzerland,- residing at Schafi'hausen, Ringstrasse 6, swazerland, have invented certain new and useful Improvements in a Device tor Truing Grinding Wheels; and I do hereby declare the following to be a clear, full, and exact description of the invention, suchas will enable others skilled in the art to which it appertains to make and use the same, reference being bad to the accompanying drawing and to letters or figures of reference marked thereon, which form a part of this specification.

This invention relates to improvements in a device for the truing of grinding wheels. Truing grinding wheels has been carried out up to the present by means;v of various tools and devices. Diamonds have been used for instance but they are best suited for the small emery-wheels of circular or surface grindingmachines. t e

For truing larger sized emery-wheels such asare in use in. work shops or foundries, the well known trimmers are used which consist of a holder carrying several small wheels of hardened steel. The latter are pressed against the quickly rotating emery-wheel in order to perform the truing.

Suchatool presents thefollowing disadthe emery-wheel is hewn until .-it runs true again. Thisis a very tedious work and if "it is not performed by .a very skilled man the danger always exists that anfemery-j wheel treated in this .way will burstwhen being putto work again. I The crumbling of the emery off the wheel edges and the formation of a ragged surface cannot. be

avoided when trimming'anemery-wheel by means of such a'hammer.

. Furthermore known lmpact tools, driven from the grinding wheel'shaft, operate .on the wheel while running atthe same speed as when grinding, which is detrimental to bethtools nd whe Specification of Letters Patent. d Patented 'Fl 28 1922'. i

' According to the present invention using dressing tools of impact type, the wheel to 1 be dressed is driven in accordancewith the operationof the tools,-so the wheel'rotat'es but slowly as compared to other dressing methods. i

Byreason of the slowi rotation of the wheel and rapid movement of the tools the dressing of the wheel canbecomple'ted in a s ngle rotation, ifthe wheel does not deviate too much from a circle. i

- A exempllfication of th'e inyention shown on the accompanying drawing in j which: i v y s n .Fig. 1 is a'plan view of the d'evice Fig. 2 is .a sideview; Fig. 3 is. a front view; .Y- 3

i Fig. 4 shots a detail, in

I Fig. is a generalarrangement view of the device fitted "to a 'fgrinding machine.

as and} at e i elevationyi I I Fig. 5 isa section along line VV Of Fig.6 is a section along line V I-'-VI of i V The foundation plate '25 of the device rest of. a grindingflmlachihe Groo es 27 fitted w two. 1 0189 150 pole to p s through i g r 'er to fix the plate" o e provided inthe foundation pl'ate .25fserve to take up a base plate 2dwhich-isadjusted l in thesegrooves so that 'thie Chisels J5 are at .a distance of'for instance .3 mm from the emery-wheel 23 when the distance .pieceji) is inserted between the stroke limiting rings 8 an d the casing 2.ofthe.chisel rams. Then I i any further displacementof plate 26 ispre vented by. tightening .nut 28. A rotation of approximately90 revolutions per minute is vimparted to the driving pulley 1 of the;de-

vice and the distance piece9 isremoved The chisels work on the emery-wheel until the stroke limiting rings :8 of the chisel rams -3. bear against the .casing2. .The .emery wheel. is then sufiiciently trimmed unless it was very-much out of true, In the latter ,--.case the device, that ',is ,to say plate manner, describedaboveand the chisels are .setv to work again.

26 is once more adjusted; with regardto the working face of a the emeryiwhe'el. J lnlthe The .driving pulley outer end of. a driving shaft which passes through all the ram casings Q A toothed w e .15; P d d w a x.eahsh -P si lar. 9 those; at. a ratch tr h9e1iszfi ed to shaft 10 in the vertical center-plane of each ram 3. The number of strokes of the rams is thus six times the number of revolutions of the driving shaft. As is s-hown in Fig. 1 in dotted lines the holes provided in the shaft :10 for thelpins with which the wheels 5 are fixed to the shaft are staggered so that the rams do not strike the emery-wheel all at the Same time but one after the other. Upon a turn ng of the "shaft the teeth of the wheels '5 push the rams 3' back and compres t e cylindrical pressure of the cylindrical springs 7.

springs 7 byengaging in their turning m otionwith face 21 of a recess 24 provlded in the ram. whereupon the rams are pushed iorward tiowards' the emery-wheel jby the i Th mpa t o th his e s a ain th sur a e f theemery-wheel has the efiect. that ralsed parts 3 a e removed from -theemery-wlieel so I tth r n ing tase'izfthe l tt i s t agaln.

A worm 17 is mounted on driving shaft 10 which engages a worm-wheelf18 mounted on shaft '12 to which rotation is thus imparted. 1 llQ Wo ki g l fl i i lmft 12 aisltll" iup-like member 13 is 'mounted, which can carry out a turning motion around the axisv of the shaft 12 that is limited bythe action of stops15 against a fixed rod 14. Between the shanks ofthe stirrup two' frictien wheels 29 are carried on a spindle 16, the circumference these friction wheels is fitted with r ubber tyres These'rubber tyres are pressed into circularigrooves ,30 provided on the 'shaft 2 1ie ythe r ta yiill n O t latter istrans m'itted to the'friction rollers 29 Furthermore the rubber tyres arepressed ain t h et ra im hf m y-di 3 by'thetorsional action of a cylindrical spring 31 on t St r p 13,, whe y he. rotary movement of the friction rollers 29 causes the emerywheel to rotate slowly. The rams 3 are slotted their working end for the purpose of inserting chisel plates therein and t eree rf d dfvfih 9 am in ie s to securely fix the inserted ch se plate in: the

(slot. A hole 6 arranged transversely to the axisof the ram provided in every ramas n nto h h a ed is in te i h gages with the Hat" surtacesof the recess24 in'the rain and prevents any turning motion ofthe latter about it's axis. a The shaft 12 can be shifted in axial directionrelatively to the worm-wheeh two further tapped holes *are provided in the 12 in which a set pin screwed inorder to fix the wormwheel in the newpositioniuon the shaft after the-"latter has been's'hiftedQ This'arrange- Inent enables obtaining a good working surface for the friction wheels nearer the center :Of'the emery-wheel, if the outer lateral part cf said wheel is much worn; e mb r wf dir d .l ree t sns to bui'ld up ens-twang eviema'y: vary aecording to the width of the emery-wheel to be trued. The rigidityaof the truing device means to fix the device at a working distance from the face ofthe grinding wheel, driving means for operating the impact-tools independently from each other, and a friction device operated bysaid driving means for imparting a rotaryfeed movement to the grinding wheel. '1 j 2. A device for truing grinding wheels,

comprising a number of mechanicallyop erated individual impact-tools fitted with removable working edges, adjustable means to fix the device at a working distance from i i the face ,of the grinding wheel; driving means for operating the impact to'ols sue,- cessively and independently from each other, and a friction device operated by "said driving means for impartinga rotary feed movement to the grinding wheel.

3. A device for truing'grindingwheels,

comprisinga number of individual nnpact tools each consisting of a spring loaded ram guided in a casing fitted with removable working edges, adjustable means to fix the devlce at i' a working distance from the face of the grinding wheel, driving means for operating the spring-loaded rams successively ing means for imparting a rotary feed movement to thejgrinding wheel. 1 1

4. A device vfor truing grindingwvheels,

and independently from each other, and zLfI'lChlOIl device operated b 'said (ii-fir.

comprising a number ofindividua impact tools each" consisting of a spring-loaded ram gulded in a casing and fitted with removable working edgesfazcommon base plate to which the individual impact-tool casings are secured, a foundation plate fixed to a support "and provided with guide grooves in which said base platejcan be ad 'j'usted and fixed so that the impart-tools are at-a' working distance from the face of w V the grinding wheel; driving meansfo1oeratingthe' spring loaded rams-successive and independently from each other; anda fr ction device operated by said driving means for imparting a rotary ment to -the grinding wheel;

5. A device for ztruing grinding wheels, comprising a number of 'individual'iimpacttools each consisting of a spring-loaded ram guided i a cas n and fitted, with remevable working'edgesymeansto fix the "deviee at";

working distance fromthe imer the t d m ,4

ing wheel, a driving pulley to which rotation is imparted, a driving shaft passing through all the impact-tool casings to one end of which the driving pulle is fixed, toothed wheels one of which is fixed to the driving shaft in each vertical center-plane of the rams, each wheel engaging with a recess provided in each ram so that upon the rotation of the toothed wheel the ram i displaced in an axial direction whereby the spring is compressed and the ram is pushed towards the grinding wheel as soon as the tooth of the wheel comes out'of engagement with the face of the recess, and a friction device operated by the driving shaft for imparting a rotary feed movement to the grinding wheel.

6. A device for truing grinding wheels, comprising a number of individual impacttools each consisting of a spring-loaded ram guided in a casing and fitted with removable working edges, means to fix, the

device at a working distance from the face of the grinding wheel, a driving pulley to which rotation is imparted, a driving shaft passing through all the impact-tool casings to one end of which the driving pulley is fixed, toothed wheels one of which is fixed tation of the toothed wheel the ram is displaced in an axial direction whereby the spring is compressed and the ram is pushed shaft said friction wheels being resiliently pressed against the lateral surface of the grinding wheel thereby imparting through the frictional action rotation to the grinding wheel. i

In a grinding wheel dresser, a plurality of mechanically operated impact tools, a driving shaft common to said tools, friction wheels for engaging the side of the grinding wheel to rotate it, mechanism to drive said wheel from said shaft, and means to permit the adjustment of said friction wheels to and from the centre of the grind ing wheel.

In testimony that I claim the foregoing as my invention, I have signed my name.

OTTO SENDER. 

